This invention will enable wireless or wireline mesh networks to detect the network topology they consist of and provide a solution on how to select the best suitable operational mode.
This invention may be applied to the following technology fields, WiFi and WiMAX network technology, mesh and ad hoc network technology, wireless sensor networks, routing and switching technology such as e.g. Ethernet, Microwave technology.
Wi-Fi is the trademark for the popular wireless technology used in home networks, mobile phones, video games and other electronic devices that require some form of wireless networking capability. In particular, it covers the various IEEE 802.11 technologies (including 802.11a, 802.11b, 802.11g, and 802.11n).
WiMAX, meaning Worldwide Interoperability for Microwave Access, is a telecommunications technology that provides for the wireless transmission of data using a variety of transmission modes, from point-to-point links to portable internet access. The technology is based on the IEEE 802.16 standards.
3GPP LTE (Long Term Evolution) is the name to a project within the Second adjacent Generation Partnership Project to cope with future technology evolutions. Goals include improving spectral efficiency, lowering costs, improving services, making use of new spectrum and refarmed spectrum opportunities, and better integration with other open standards.
It has become an important topic for wireless cellular communication such as WiMAX and LTE to integrate multi-hop capability by deploying relay stations (RS). For example, IEEE has established a relay workgroup in order to introduce relay stations into systems based on IEEE 802.16 standards.
Mesh networking is a way to route data, voice and instructions between nodes. It allows for continuous connections and reconfiguration around broken or blocked paths by hopping from node to node until the destination is reached. A mesh network is considered to be a set of randomly arranged wireless nodes which are able to setup connections to adjacent nodes without special manual care taking required. The nodes will configure themselves in a way that optimal routes are setup by employing packet based routing schemes on Data Link or Network Layer of the Open System Interconnection (OSI) reference model.
Setting up a mesh configuration may be necessary when the nodes may are placed in a complete disordered manner. This may happen during setup phase of a communication network or when nodes drops or links are broken randomly.
Mesh networks can be seen as one type of ad hoc network. Mesh networks are self-healing: the network can still operate even when a node breaks down or a connection goes bad as it may happen that the whole set of nodes or a significant number of nodes arrange themselves in a more ordered way. As a result, a very reliable network is formed. This concept is applicable to wireless networks and wired networks.
Wireless mesh networks are the most popular representatives of mesh architectures. The mesh nodes may also support multiple radio cards, each operating at a different example given frequency, code or timeslot.
Mesh routing and switching protocols are subject of standardization, mainly in IEEE 802.11 s and IEEE 802.16j.
A wireless ad hoc network is a decentralized wireless network. The network is ad hoc because each node is willing to forward data for other nodes, and so the determination of which nodes forward data is made dynamically based on the network connectivity conditions. This is in contrast to wired networks in which routers perform the task of routing.
A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations
Ethernet is a family of networking technologies for local area networks (LANs). It defines a number of wiring and signaling standards for the Physical Layer of the Open Systems Interconnection (OSI) reference model, through means of network access at the Media Access Control (MAC) of the Data Link Layer (DLL), and a common addressing format. Ethernet is standardized as IEEE 802.3.
Microwave radio relay is a technology for transmitting digital and analog signals, such as long-distance telephone calls and the relay of television programs to transmitters, between two locations on a line of sight radio connection.
Networks are arranged in daisy chain manner when each node is connected in series to the next. If a message is intended for a node down the line, each node forwards it along in sequence until it reaches the destination.
By connecting the nodes arranged in daisy chain manner at each end, a ring topology can be formed. An advantage of the ring is that the number of transmitters and receivers can be cut in half, since a message will eventually loop all of the way round. When a node sends a message, the message is processed by each node in the ring. If a node is not the destination node, it will pass the message to the next node, until the message arrives at its destination. If the message is not accepted by any node in the network, it may travel around the entire ring and return to the sender.
The document EP000115476 Hauenstein et al discloses a method for e.g. virtual local area network, building up topology data base describing network topology based on reported received topology descriptors by central host.
In today's fixed and wireless communication networks there is most often a constellation where data forwarding nodes have connectivity to more than one or two adjacent nodes which allows more than one option or choice for routes.
A typical example is a routed network where one IP router has connectivity to many IP routers, so packets transferred from one peer end of a network to another peer end of the network may use different routes across the network utilizing different IP routers, in the extreme case for each packet.
Another example is an Ethernet network where packets may cross different switches, hubs or bridges of a layer 2 network.
Whenever there is more than one choice of routes to choose between the number of possible routes scales up dramatically with the number of nodes involved—but still there may be only one of these routes which is optimal in terms of QoS and reliability for each connection and only the selection of all the best possible routes for all connections will allow to run the whole network appropriately.
It is one of the most innovative areas to find clever algorithms to determine the optimal routes, and there are a lot of algorithms and methods on how to achieve this.
In routed networks there are different variations of routing protocols engaged which can be classified into proactive routing protocols such as OLSR (optimized link state routing), reactive routing protocols such as DSR (dynamic source routing) and hybrid routing protocols such as ZRP (zone routing protocols)
The algorithms behind are manifold and are specialized for different use cases each having there own pros and cons.
There are numerous ways on how to best handle path finding and mesh configuration. One prominent example on how to deal with both, path finding and dynamic changes is the Hybrid Wireless Mesh Protocol (HWMP) as recommended by IEEE 802.11s. Here a combination of proactive (long haul) and reactive (local) routing protocol is engaged to best cope with mesh problems.
In case of point-to-point wireless connections even more techniques can be applied, such configurations are typically used for microwave links. In general, depending on the nature of the air interface, a carrier, a timeslot (Time Division Multiple Access) or a frequency (Frequency Division Multiple Access) is dedicated to a link.
However, point-to-point connections are considered to be employed in static environments, manually configured, where as highly dynamic systems are considered to be employed in mesh or adhoc networks environments.
Route and path finding in adhoc or mesh networks may be deployed in municipal networks, emerging countries, new players setting up competitive access networks but also industry environment like wireless metering and sensor networks.
Selecting the best possible route is even more important if the nodes are connected via links which may show instability or changing quality like wireless links. Furthermore, additional challenges arise when the connectivity between the different nodes changes frequently i.e. because new nodes are added or removed, nodes are moved or radio conditions change.
This is typical for so called mesh networks and adhoc networks—wireless connection nodes are rearranged occasionally so the routes may change frequently. In this case, in addition to the known route-finding problem the issue of high dynamic comes on top.
Mesh technologies differentiate themselves towards the state-of-the-art technologies by being very dynamic in terms of packet delivery and route finding—which may mean each packet taking a different route.
A typical example of a non meshed technology may be distinct point-to-point connections, i.e., nodes are interconnected by fixed links and all the traffic from one edge of the network to another edge of the network will use fixed routes which are predefined by fixed links. A terminology commonly used for this type of setup is “switched mesh” indicating that one node may have connections to more than two other nodes. However, the traffic will always use the same routes unless a link is broken.
“Switched mesh” is mainly used in static scenarios with no change of topology where as real mesh is used in highly dynamic environments.
The use of resources, especially in case of wireless telecommunication networks environments, is extremely different for meshed and non-meshed use cases.
Using mesh technologies in telecommunication environments requires a per-packet handling with frequent update of the routing tables, high meshing overhead, additional delay caused by mesh but provides highly dynamic but self healing capabilities.
The non-mesh telecommunication environment provides continuous availability of links, stable quality of service (QoS), no or minimum delay, quasi circuit switched mode and no or few flexibility.
This invention provides a method which allows operating in an optimized topology mode once mesh systems are setup.
It may be advantageous, not to use mesh mechanism when networks are arranged in daisy chain manner as the traffic may only be forwarded along the chain there. The use of meshing or routing schemes does not necessarily provide the most effective network connection for these scenarios. Instead it may be more advisable to setup fixed point-to-point connections, so the spare resource of the air interface may be utilized best.
There are also other configurations which predict a use of the air interface different to typical mesh and it may advantageous using the best suitable setup.
But before the best suitable mode as e.g. mesh, non mesh, circuit switched or routed can be employed, the telecommunication network in part or in total may be able to recognize what sort of network topology will apply to it. The task of the present invention is the detection of a network topology type and employing of an appropriate network topology mode in a telecommunication network environment.